Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Mol Phylogenet Evol. 2018 Oct;127:146-155. doi: 10.1016/j.ympev.2018.05.026. Epub 2018 May 24.
The Cretaceous experienced one of the most remarkable greenhouse periods in geological history. During this time, ecosystem reorganization significantly impacted the diversification of many groups of organisms. The rise of angiosperms marked a major biome turnover. Notwithstanding, relatively little remains known about how the Cretaceous global ecosystem impacted the evolution of spiders, which constitute one of the most abundant groups of predators. Herein, we evaluate the transcriptomes of 91 taxa representing more than half of the spider families. We add 23 newly sequenced taxa to the existing database to obtain a robust phylogenomic assessment. Phylogenetic reconstructions using different datasets and methods obtain novel placements of some groups, especially in the Synspermiata and the group having a retrolateral tibial apophysis (RTA). Molecular analyses indicate an expansion of the RTA clade at the Early Cretaceous with a hunting predatory strategy shift. Fossil analyses show a 7-fold increase of diversification rate at the same period, but this likely owes to the first occurrence of spiders in amber deposit. Additional analyses of fossil abundance show an accumulation of spider lineages in the Early Cretaceous. We speculate that the establishment of a warm greenhouse climate pumped the diversification of spiders, in particular among webless forms tracking the abundance of insect prey. Our study offers a new pathway for future investigations of spider phylogeny and diversification.
白垩纪经历了地质历史上最显著的温室时期之一。在这段时间里，生态系统的重组极大地影响了许多生物群体的多样化。被子植物的兴起标志着一个主要的生物群落更替。尽管如此，关于白垩纪全球生态系统如何影响蜘蛛进化的信息仍然相对较少，蜘蛛是最丰富的捕食者之一。在此，我们评估了代表超过一半蜘蛛科的 91 个分类群的转录组。我们向现有的数据库中添加了 23 个新测序的分类群，以获得稳健的系统基因组评估。使用不同数据集和方法的系统发育重建获得了一些群体的新位置，特别是在 Synspermiata 和具有retrolateral tibial apophysis (RTA)的群体中。分子分析表明，RTA 进化枝在早白垩世扩张，其捕食策略发生了转变。化石分析表明，同期的多样化速率增加了 7 倍，但这可能归因于蜘蛛首次出现在琥珀矿床中。对化石丰度的进一步分析表明，蜘蛛谱系在早白垩世大量积累。我们推测，温暖的温室气候的建立促进了蜘蛛的多样化，特别是在追踪昆虫猎物丰度的无网形式中。我们的研究为未来的蜘蛛系统发育和多样化研究提供了新的途径。
